To provide a platform suitable for purification of tumor-derived vesicles and to separate them from other tissue-derived vesicles in biofluids, we propose a two-step approach: 1) Aethlon Medical?s Hemopurifier device for isolation of the total exosome population from biofluids such as plasma. This affinity biofiltration technology employs hollow-fiber hemofiltration cartridges (average 200 nm pores) containing the lectin Galanthus nivalis agglutinin (GNA) as an affinity agent, which has been leveraged for capture of a broad spectrum of viruses of similar sizes and high mannose-glycoprotein surfaces as exosomes. This clinically-used device has been scaled down to a bench-top version capable of filtering large volumes of complex biofluids, thereby overcoming limitations of current exosome isolation techniques. 2) Magnetic immunocapture of tumor exosomes using the mAb 225.28 recognizing an epitope of chondroitin sulfate proteoglycan 4 expressed on tumor exosomes. The Co-Investigators, Drs. Whiteside and Ferrone, have demonstrated the ability to perform magnetic isolation of melanoma exosomes using mAb 225.28. By leveraging a device platform specialized for rapid processing biofluids followed by immunocapture with mAb 225.28, the proposed work aims to standardize an exosome isolation method from complex biofluids that will be suitable for automated workflows in research and clinical care.